Field of the Disclosure
The present disclosure relates to wireless communication systems, for example, and more particularly to non-orthogonal multiple access and interference cancellation.
Description of the Related Art
Wireless communications networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.
A wireless communications network may include a number of base stations, that can each support communication for a number of user equipments (UEs). A UE may communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems. Additionally, some systems may operate using time-division duplex (TDD), in which a single carrier is used for both uplink and downlink communications, and some systems may operate using frequency-division duplex (FDD), in which separate carrier frequencies are used for uplink and downlink communications.
As wireless communications networks become more congested, operators are seeking ways to increase capacity. Various approaches may include using small cells, unlicensed spectrum, or wireless local area networks (WLANs) to offload some of the traffic and/or signaling. Many of the approaches for enhancing capacity may cause interference with concurrent communications in a cell, or in adjacent/neighboring cells. For example, a UE in one cell may be transmitting uplink communications while a base station in a neighboring cell may be transmitting downlink communications at a signal strength that may interfere with the uplink communications from the UE. In other examples, interference may arise from radios operating in adjacent frequency bands. In order to provide enhanced data rates through a wireless communications network, it may be beneficial to mitigate such interference at a UE or a base station.